1. Field of the Invention
The present invention relates to a fluid diversion apparatus and in particular to an apparatus wherein a single fitting allowing a portion of the fluid to be diverted, manipulated and then reintroduced, is attached to the main fluid flow line.
2. Background Art
Methods and apparatus for dispensing treatment products into a liquid stream are known. These methods usually involve the use of power-driven or electrical metering pumps. These pumps apply a force to the additive and through this, move the additive into the liquid stream. The dispersal is left to the inherent vortices and eddies in the fluid stream.
Also the “bypass” type fluid diversion apparatus is known. These are generally associated with chemical feeders or dispensers. In this type of known diversion apparatus, the system comprises a main flow stream pipe in which the fluid to be treated flows in one determined direction. For the purposes of introducing fresh untreated liquid to the chemical dispenser, the dispenser is fitted with an inlet port. For the purpose of providing outflow, the chemical dispenser is fitted with an outlet port. The inlet port is connected by a suitable conduit to the upstream side of the pipe. In a like manner, the outlet port is connected to the downstream side of the pipe by means of a conduit.
In order to provide optimum flow control and thereby control the amount of chemical added to the liquid stream, a pair of valves are generally provided, one on each conduit. These valves provide a means for stopping flow through the dispenser for servicing and addition of chemical product. They also are generally sensitive, to provide an accurate control over both the flow of fresh liquid into the dispenser and the quantity of solution being drawn from the dispenser and added to the flow stream.
In order to provide for adequate flow of liquid through the dispenser in the direction desired, a restriction is provided in the main line between the inlet conduit and the outlet conduit which creates a pressure differential across the inlet and outlet of the dispenser so as to direct the flow as desired. Generally, a venturi is provided, converging in a direction towards the outlet conduit and having a throat of sufficient restriction to provide a pressure differential which is adequate to permit the required flow to be attained through the chemical dispenser.
In a second known configuration, the restriction is a throttling valve placed on the main flow stream pipe, between the inlet conduit and outlet conduit valves. By closing the valve, a pressure differential is created across the inlet and outlet of the dispenser so as to direct the flow as desired.
In a third known configuration, a dip tube type of bypass diverter is used, wherein a tube having an entry hole is placed in the main flow stream line, perpendicular to the direction of flow. This entry hole allows for a scooping up of liquid, which then proceeds to the dispenser and is sucked back into the main flow at a second downstream tube also perpendicular to the direction of the main flow stream. The second tube, which returns the fluid to the main flow stream, typically has an angled tip, with the angled portion facing away from the direction of flow.
In the above configurations, the apparatus requires the use of two conduits (generally tee-fittings), and this is disadvantageous when an installation is required in a tight area lacking access. Alternative bypass arrangements require other fittings or adaptations be made to the main stream pipe and so hamper the construction of the apparatus. The throttling valve and venturi rely on the pressure created to drive the bypass liquid through the dispenser, not ram type pressure of the liquid due to its velocity in the main stream pipe.
The bypass-type fluid diversion apparatus provides a useful alternative to using metering pumps, which can be expensive and also require maintenance. The fluid diversion apparatus as described here can also be replaced in the event of problems, far more easily than a valve or venturi which will be generally securely attached to the main flow stream pipe usually by welding or brazing. It is also less often in need of maintenance due to the use of corrosion resistant materials in manufacture.